Treatment of material in a vacuum and apparatus



Aug. 10 1926iV O. MINTON TREATMENT OF MATERIAL IN A VACUUM .AND APPARATUS Original Filed March 4. 1920 3 Sheets-Sheet 1 '3 Sheets-Shes?l 2 O. MINTON ,TREATMENT 0F MATRIAL IN A VACUUM AND APPARATUS Original Filed March 4. 1920 Aug. 10, 1926.

B o W Aug. 10 1926. 1,595,475

o. MINTQNv- TREATMENT OF MATERIAL AIN A .VACUUM AND APPARATUS Original Filed March 4, 1920 3 Sheets-Sheet 3 VENTOR BY Z( ;ATTORNEY Patented Aug. 1o, 192s. j

UNITED sTATEs PATENT OFFICE.

OGDEN MENTON, OF GREENWICH, CONNECTICUT.

Application led March 4,1920, Serial No. 363,351. Renewed February 1.7, 1988.

The present invention relates to an apparatus and method for the drying of paper and other sheet material, in a vacuum chamber, and then immediately, while still in l the vacuum chamber, coating, or coloring, or sizing or'impregnating the paper or other sheet material, and then immediately drying the coated, colored, sized or impregnated paper or other sheet material while still in the vacuum chamber.

My improved method consists in passing the sheet material which is to be dried into a vacuum chamber through a liquid sealing medium which has no ainity for the material, subjecting it. to heat to drive o' its contained moisture, immediately coating or coloring, or sizin or impregnating the sheet material whi e in the vacuum cham-` ber, then subjecting the coated or colored,

or sized or impregnated sheet material to heat to drive off its contained moisture or other liquid, and then passing the sheet material out of the chamber through a seal. This method may be practiced by the use of various forms of apparatus, some of which are herein disclosed.- In any -form, however, it is essential that the apparatus be provided with a closed chamber in which a partial vacuum maybe maintained. In

o order that the material to be dried, treated, and again dried may be continuously passed through the vacuum chamber, the latter is provided )with openings closed to the admissionf air by a liquid sealing medium which has no aflinity for the material. The liquid seal effectively closes the lentrance and exit passages against the admission of air to the chamber, but permits the passage of the material into and out of the chamber.

The heating elements within the vacuum chamber, for drying the material, the shape, form, dimensions and location of the liquid seal containers.. and the means for passing the sheet material through the chamber,

may all vary. I have shown herein a number of varieties'which I contemplate using- My invention further relates to withdrawing from the sheet material substantially all, or ai large portion, of its occluded x air. and lling the interstices normally filled by the occluded air with a coating of impregnating compound, and then drying said coated or Vimpregnated sheet material in the Vacuum chamber before subjecting the said 55, sheet material to atmospheric conditions.

I My invention further relates to obtaining a better and more uniform product than any now known on the market. My invention further relates to the method of coating or impregnating sheet material which insures that there will be no blemishes, uneven surfaces, blisters or minute raised rtions due to the air which may be hel or occluded within the sheet material which, in the present practice of coating as for example with a lwater-proof compound, leads to rejections or discards due to these imperfections with the consequent waste of material and labor.

My invention further relates to the treatment of paper, either from the wet end of a paper machine or from a roll or reel of wet or damp paper, feeding the web of wet or damp paper into a vacuum chamber without breaking the vacuum, drying said web' in the vacuum chamber, and removing substantially all ofV its ocoluded air, and immediately coating or impregnating or coloring said dryweb with a coating or impregnating or coloring compound, and then again drying the web, the second time with its coating or impregnating or coloring compound, within the vacuum chamber and all these steps being ,continuous and prior to subjecting the coated or impregnated compound to the action of the atmosphere.

My invention further relates to manufacturing paper wherein the ibers are not weakened and the size in the paper is not injured or damaged dueto drying at high temperatures.

My invention further relates to manufacturing colored paper and drying it without substantially impairing the coloring matter and mordants used in the paper.' Among other advantages this insures that the paper will have bright colors, which will be substantially uniform in different runs of paper, permitting matching of colored paper without any appreciable difference in tone or color.

My invention further relates to rapidly and expeditiously coating or lmpregnatlng sheet material in a continuous web or sheet. My invention further relates to sizing paper in a vacuum chamber and drying the sized paper in said vacuum chamber at such low temperatures as not to injure theA fibers of the paper -or the size. My inyention further relates to withdrawing the occluded air from the aper and immediately drying and then filling the intersticesmnor- .su jected to atmosphericv conditions.

l' the vacuum chamber Without breaking the vacuum. My invention further relates to certain steps, and combinations of steps, also to certain elements and comblnatlons of elements, whereby the method or processes herein described may be carried out, as Well as to certain details of construction, all of which will be more fully hereinafter described in the specification and polnted out in the claims.

The accompanying drawings, whlch are partly diagrammatic illustrate several, but not the only, -forms of my apparatus, by the use of which my improved method may be practiced.

In the accompanylng drawlngs the same reference numerals refer to similar parts 1n the several figures.

Fig. 1 is a vertical diagrammatic sect1on through one form of apparatus which mayl be used to carry out my improved process;

Fig. 2 is a diagrammatic vertical sect1on of a modified form in which the Web of sheet material is passed through a heated bath to dry the same;

Fig. 3 is a vertical diagrammatic sect1on of a modified form of apparatus 1n which a combination of heated drums and a heated bath are used to dry and finish the sheet material;

Fig. 4 is a vertical diagrammatlc sect1on Aof another modification in which different sized drums are used with a heated liquid bath to vary the finish given to the sheet material;

Fig. 5 is a vertical diagrammatic sect1on of still another modification in which the web of sheet material is passed in folds or loops through the vacuum chamber adjacent to but not in contact with fixed heating surfaces; and n Fig. 6 is a vertical diagrammatic sect1on of still another modification in which the web of sheet material is fed through the vacuum chamber, and in its passage through said chamber subjected to radient heat, preferably a glowing member of an electric eater.

In describing my invention I will describe it as applied to sheet material in the form of paper though it is to be distinctly understood that textile fabrics may also be treated by my process and that my broader claims cover all forms of materials.

In the ordinary drying of a web of paper such high heat is used as to injuriously affect the fibers of the paper; and in case the paper is colored it will materially affect the coloring matter and mordants used. Drying paper in the hightemperatures used in ordinary practice often affects the size so that the resulting paper varies in quality, is not uniform and is not a perfect product.

In coating or impregnating fabrics it is found in practice that the coated fabric will frequently have blemishes duc to large or small blisters and blow holes, these often being about the size of a pin-head or a pinoint. This is caused by the air which is eld or occluded being collected, more or less, in small pockets under the coating or impregnating material, or in some cases causing minute blow holes. In Water-proof fabrics this results in large quantities of the material being rejected with the consequent loss to the manufacturer.

By my invention I insure that substantially all the occluded air is withdrawn from the sheet material which will permit the coating or impregnating material, whatever it may be, to thoroughly fill these minute interstices or pockets normally occupied by occluded air, forming thereby a better .and more uniform product and one devoid of blisters, blow holes or such blemishes. By my invention I immediately dry such coated or impregnated sheet material While still in the vacuum chamber so that when the sheet material emerges from the vacuum chamber the coating or impregnating material is dry and set without any danger of atmospheric pressureV or atmospheric conditions spoiling or marring the finished product.

As previously stated I will describe my invention with relation to coating or impregnating paper, though it is to be understood that textile fabrics may be treated in the same manner.

The web of paper l is fed direct from the Wet end of a paper making machine, or in some cases it may be fed from a roll or reel 2 of wet or damp paper. The web is fed into the vacuum chamber 3 by passing over the guide roller 4. into the liquid seal 5, under the submerging roller 6` and thence in Contact with the guide roller 7. This liquid seal 5 may be of any suitable material which has no affinity for the sheet material treated and has no deleterious effect upon it. Preferably I use mera-uri' as the sealing medium 5, but it is to he distinctly understood that any amalgam, alloy,.or any other suitable liquid sealing mediumfmay be employed which has the characteristics above specified.

The web l is immediately upon its entry into the vacuum chamber 8 dried preparatory to4 coating or coloring or impregnating it. I have shown in Fig. 1 a revolving drying drum or cylinder 8, which is` heated in any suitable manner, and over which thi` web 1 passes and is dried preparatory to entering the coating or impregnating bath 9. It may be ,fed into the bath in any suitable manner as by engaging with the guide rciier 10 and under the submerging roller 11 in the chamber 12` containing the coating or coloring or impregnating bath 9. This bath may be of any suitable material to coat or impregnate or color sheet .material` whether it be paper or textile fabric. Slmply by way of example. this coating or impregnatingbath 9 may be size, tar, wax, or in fact any coating or waterproofing` or impregnating or coloring compound. The web is then fed through the squeeze rollers 13 13, which remove all the surplus coating or coloring or impregnat-ing compound, thence in contact with the guide roller 14 and over the second revolving healing drum 15, which completely dries the web with its coating or impregnating compound, thence .in contact with the guide roller 16 and out through the second liquid seal 5 under the submerging roller 17 and over' the guide roller 18` where the web 1 is preferablywound into vthe finished roll or reel 19.

' This second liquid seal will preferably heated if desired by passing steam or be of the same materiall as the first seal 5, thou h of course it may befvaried provide it has no affinity .for or deleterious mainture but also substantially all of its occluded i airn so that while` in this condition with its mterstices, normally filled with occluded air free of such airit passes immediately into `the coating or'- impregnating bath 9 so that a better application of the coating or impregnating compound will be had because portions of the bath will fill these minute intersices in the web.

The drying drums o r cylinders maybe heated by exhaust steam or hot water, or otherwise. Their temperature may be varied within quite Wide limits but they must not be heated Ato such a era'ture as to injuriously effect the material treated, or the size, or coloring matter or mordants, if such bel used.

If the coating or impregnati' material 9 1s a compound including high y volatile liquids, these volatile ,liquids will of course boil or be given ofl'- at a' lower- `temperature than that, given above.

,In my invention I thoroughly dry the affect upon the finished dry -coated or rmfGOaed K01 impregnated web yat a relatively pregnated web 1.

While I have shown one drying drum 8 to dry the web prior to coating or impregnating it within .the vacuum chamber, -it is of course understood that a greater umher of drying drums may be used if found nefessaryorconvenient. This also applies to the number of drying drums 15 t-o dry the webafter ithas been coated or imprec-nated.

The coating or impregnating compound 9 may be fed into the chamber 12 in any suitable manner such as by operating the cock 20 in the supply pipe 21. The material of the bath 9 may be Withdrawn and the chamber 12 cleaned, preparatory to using a different coating or impregnating compound, in any suitable manner` such as for examplebv operating the cock 22 in the pipe 23. This coating or impregnating bath mayhbe ot water through the pipes 24. The vacuum chamber 3 is provided with exhaust -pipes 25, 25 and is connected to any suitable form of vacuum machine or condenser to maintain the particular degree of vacuum within the 'chamber desired, and at the same time Withdraw the steam, moisture, air, and other vapors given off by the web of paper as it dries. If the coating or impregnating material includes volatile liquid, which it may be desired to recover and use over again` this may be done in any well known blisters or defects due to small portions ofair being held under any of the coating; orseeking to escape therefrom, causing pinholes to appear on the surface. In passing the web over the revolving drying drums or (ylinders it is given a flat and smooth surace.

In some cases it is desirable to give a different finish tothe web than that which is given bv the drying drums or cylinders of Fig. 1f lVhen the web 1 is of paper.

it is also desirable,in some cases, to let the fibers of the web shrink under little 'or substantially no tension, so that the resulting sheet or web is substantially as strong lengthwise of the sheet as it is cross'wise.

I have shown a modification in Fig. 2, in which the web 1 is fed from the wet end of a paper machine, or from a reel 2in the `same manner as in Fig. 1, into the vacuum chamber 25, through a; similar liquid seal 5. In this form of my inventionjth'e-web passes over the guide roller 26g'and vinto,

a heated bath .27 of some medium which willldry the web but which has no affinity.

for, or deleterious action upon it. Preferably this heated bath is mercury, which may be heated in any suitable manner as by the steam pipes 23, 2S. It is to be distinctly understood, however, that this heated bath may be any amalgam, alloy, or any other rollers 13, 13 which remove all surplus coating or impregnating compound, thence over the guide roller 34 and into the second heated bath 35 uder the submcrging rollers 36, 36 and over the guide rollers 37, 37. This bath 35 is one having the same characteristics as the first liquid bath 2T. The web, non7 coated or impregnated, in passing through the second heated bath 35 is thoroughly dried and the coating or impregnating compound is set so when it passes out of the vacuum chamber through the second liquid seal 5, under the submerging rollers 17 and over the guide roller 18 it is a finished and dry product ready to be immediately rolled into a roll or reel 19.

In some cases it may be desirable to give the web 1 a finish and smoothness different from what it is given in the apparatus, shown in Figs. 1 and 2. I may for example pass the web 1, Fig. 3, into the vacuum chamber 38 through a similar liquid seal 5 and over comparatively small guide rollers 39, 39 and in contact with relatively large submerging rollers 40, 40 which may be heated and rotated, or not, as found convenient or desirable. These rollers 40, 40 are mounted in the liquid bath 41 preferably of mercury, though of any suitable medium having the characteristics previously described in connection With the baths 27 and 35, Fig. 2. The liquid in this bath may be heated in any suitable manner as by steam, hot Water or products of combustion passing through the chamber 42.

yAfter the web 1 has been thoroughly dried b v its passage through this bath 41 and in contact with the drums 40, 40 the guide rollers 39, 39 it is immediately, While still in the vacuum chamber, passed into the compartment 43, containing the coating or impregnating liquid 9, thence through theJ squeeze rollers 13, 13 over the guide roller 44 and-through the second liquid bath 45, while in contact with the drums or rollers 46, 46; the web passing over the guide rollers 47, 47. The liquid bath 45 is pref- -tially thc same size as the similar elements or fibers of the web. It is then vpassed out of the vacuum machine through the second liquid seal 5 under the submerging rollerjl'l and over the guide roller 18 Where it may be immediately Wound into a finished roll of coated'or impregnated paper or fabric 19. A

The finish of the Web, particularly if it is of paper, may be still further varied by changing the size of the rollers 39, 40 and 46 and 47. These changes maybe made Within Wide limits. Simply for purposes of illusstration I have shown in Fig. 4 another variation ot' my invention in which the vacuum chamber 49 is provided with the same liquid baths 41 and 45. The guide rollers 50, 50 of the first Vliquid bath and the guide rollers 52, 52 ot the second liquid bath are-substanguide rollers of Fig. 3, but the drums 51, 51 of the first liquid bath and the drums 53, 53 of the second liquid bath are smaller than the corresponding drums 40, 40 and 46, 46 respectively, of Fig. 3. In this modification the web 1 will not have a finish quite so flat and smooth as given by the apparatus shown in Fig. 3 or that shown in Fig. 1, but Will give a flatter and smoother finish than the apparatus of Fig. 2. While these different forms are shown, it is of course to be understood that they are simply illustrative and that my invention is not to be confined to them.

The forms shown in Figs. 2 to.4 are the subject of my divisional application, Serial No. 545,218.

'It is desirable in finishing some webs of sheet material, particularly paper, to pass -them adjacent to, but not in contact with the heating elements. I have shown in F ig. 5 a vacuum chamber 54 provided with fixed heated elements 55, 55. These elements are preferably heated with steam or hot Water. The web 1 of paper coming from the wet end of a paper machine, or from the roll 2, is passed through a portion of the vacuum chamber 54 in folds or loops 56, 56 with little or no tension upon it, only such as is sufiicient to insure its proper passage over the guide rollers 57, 57 and 58, 58 and through the apparatus. Between one or more of these folds or loops 56, 56, preferably between each of the folds, I mount one of the fixed heating elements 55, 55 so that the web tially high vacuum In passing from this bath the squeeze rollers 13, 13 will -remove the surplus liquid prior to the web passing over the vguide roller 62 and through the compartment 63 of the vvacuum chamber in' contact with the guide rollers 64, 64 and 65, 65. Between one or. more, preferably ybetween each one of the folds or loops 66, 66 of the coated or impregnated web 1, I mount a fixed heating element 67, 67 which is heated by steam or hot p water, and is in all respects, similar tothe elements 55, except that they are mounted in that portion of the vacuum chamber that is used to web.A After passing through the compartment 63-to' the guide roller 68, the .web will have been dried at a comparatively low temerature and one which does not injure the 'bers of the paper, it being well known thatevery time the iib'ers of paper are subjected to a high temperature they areniore or less injured resulting in an inferior product. The web isthen fed out of the vacuum cham'- ber through the second liquid' seal 5, 'under roller 17,A over the guide although not necessarily, rolled or reeled into the finished roll 19.

In some cases I may use a vacuum' chamber 69 Fig. 6, in which the web 1 is fed through in folds or loo s 70, 70 and in its passage is subjected to t e action of radient heat, preferably the glowing member of an electric heater 71.. By the time the web reaches the uide roller 72 the web will be ro er 74 thoroughly ried and substantially all of its occluded air will be removed by the vacuumin tlie chamber. It is then passed into the compartment 73 containing the liquid or im regnatingbath 9,'then over 'the guide, where it is again passed in folds or loops 75, 75 through the portion 76 of the vacuum chamber. he coated or impregnated web is also preferably subjected to lowing members of other electric heaters 77, 77 mounted in the compartment 76, so that when the coated or impregnated web reaches the guide roller 78 it will be thoroughly dried and the coating or impregnating material will be thoroughly dry and set before the web passes out of the second liquid sealy 5, under the submerging roller 17 and over the guide roller 18 w be wound into the finished roll or reel 19.

The forms illustrated by dry the coated or impregnated operatin trol of t e drying can be closely standard- Figs. 5 and 6 are s 1 the subject of my divisional application Ser.

method is very the atmospheric cylinder drying heretofore in universal use for drying pap much greater thanthat of er. Theoretically, it requires about 5287 pounds of steam to dryone ton of paper at atmosphericv pressure,'but to compensate for convection and conduction losses, leaks in the piping system, and other inediciencies, it has been shown iii practice that about 10,600 pounds are required.

at which the water. is evaporated from the` aper insuch' open air dryers much below 212 F., and may, in some cases, reduce the temperature yof evaporation as low as 180 -FQ or lower.

In my method, using a.vacuum of about 28, the convection, conduction and piping `losses are exceedingly small and the tota steam required to dry a ton of paper by my method is approximately 5200 pounds.

Itis an established fact that paper dried at low temperaturesl is much stronger than when it is dried at the high temperatures used in paper machine atmospheric drying. Paper dried inra vacuum of 28, or at a temperature of about 100 F., as in my method, `is very much stronger than `paper dried att atmospheric pressure, .when the steam in .the driers is at 228 When paper is dried by my method, therefore, a cheapenfurnish can be used and still produce a coated or impregnated or sized paper equal in strength to atmospheric dried paper, n which a higher grade furnish is used. making newsprint paper, I am able to dispense with a considerable portion of the more expensive sulphite pulp, as this c an be replaced with the cheaper ground wood pulp. By my method I also reduce the number of breaks in the web as it passes over the cylinder.

Furthermore, in my method there is a great saving of heat (or steam) because the process is carried on in a vacuum chamber. which acts ony the principle of a thermos bottle, and the steam and vapors driven out ofthe wet paper are caught in the closed vacuum chamber,` and conducted away to the condenser. The operating1 rooin is free from steam, humidity and eat, and fans, and exhausters are dispensed with. In the use of my method the apparatus is at all times under definite humidity, the conized, and the moisture content in the paper carefully regulated.

By m process and apparatus the wet or damp web of sheet material, whether it be paper or textile material, is dried in a vac uum chamber and is rapidly coated or coland those due to` through atmospheric conditions insure' that the sheet' material will not be injured inany particular and that the process may be speeded up, thereby reducing the cost of manufacture. The sheet material is never subjected to, high temperatures. which high temperatures invariably injure its bers or threads. I am enabled also to use a comparatively small machine, which takes up comparatively small floor space thereby reducing overhead expenses..

I. Having pointed out the many advantages of my method and apparatus over those heretofore used, it Will be apparent 'that the use of my invention results in great economy in the initial cost of apparatus and in large savings in cost of operation, maintenance and repairs.

Having thus described this invention in connection with illustrative embodiments thereof, to the details of which I do not de; sire to be limited, what is claimed as new and what is desired to secure by Letters Patent isset forth in the appended claims.

What I claim is y 1. The method of treating sheet material consisting in feeding it into and out of a vacuum chamber Without breaking the vacuum, drying -the sheet material in the vacuum chamber under slight tension suiii-v cient to cause its constituent elements to slightly rearrange themselves inl the direction of travel of the sheet material thereby giving a smooth and flat surface to the material treated, then coating, sizing or impregnating the sheet material While still in the vacuum chamber, and then immediately drying the coated, or impregnated or sized material While still in .the vacuum chamber and prior to passing it into the atmosphere.

2. The method of continuously treating sheet material consisting in feeding it intoV and `out of' a vacuum chamber without breaking the vacuum, the sheet material in the vacuum chamber under slight tension suicient to cause its constituent elements to slightly rearrange themselves in the direction of travel of the sheet material thereby giving a smooth and fiat surface to the material treated, then coating, continuously Vsizing or impregnating the sheet material While still in the vacuum chamber, and then immediately and continuously drying the coated, or impregnated or sized material While still in the vacuum chamber and prior to passing it into the atmosphere.

3. The method of treating a Wet web of .paper consisting in feeding it continuously into and out of a vacuumchamber Without breaking the vacuum, drying the Web in the. vacuum chamber and at the same time putting the fibers under more or less tension so that they will be pulled-out slightly in the direction of travel of the continuously drying web, coating, sizing or impregnating the web of paper in the Vacuum chamber, and then While still in the vacuum chamber dry? ing the coated, sized or impregnated Web of'paper and giving it a smooth fiat surfa before permitting it to pass into the atmosphere. v A

,4. An apparatus for treating a web of paper, including a vacuum chamber, means to permit the web of paper to pass into and out f of the -vacuum chamber continuously Without breaking the vacuum, drying means located in the vacuum chamber to dry the web and at the same time to cause .its constituent fibers to slightly rearrange themselves from the position assumed by them on the Wire of the paper machine thereby giving a smooth flat surfaceto theweb of paper, means Within the vacuum chamber to coat or size or impregnate the Web, and other drying means mounted in the vacuum chamber to dry the coated or sized or impregnated web of paper prior to its continuous passage into the atmosphere.

OGDEN MIN TON. 

